I am looking at someone code and it uses <: when creating a struct. I looked in the docs and found out that this means they are creating an abstract supertype. Can anyone explain what this is an...

Consider the following Java class declaration: public class Test { private final int defaultValue = 10; private int var; public Test() { this(defaultValue); // <-- Compiler error: cannot ...

I have googled couple of times but still can't understand the supertype method. Can anyone please explain what is this?

I am working on a program in which you can register complaints. There are three types of complaints: internal (errors from employees), external (errors from another company) and supplier (errors ma...

I m trying to get the annotation details from super type reference variable using reflection, to make the method accept all sub types. But isAnnotationPresent() returning false. Same with other ann...